Compensating lever mechanism for shears



NOV. 3, 1936. J LIBERT 2,059,644

COMPENSATING LEVER MECHANISM FOR SHEARS Filed Oct. 22, 1930 3 Sheets-Sheet l Nov. 3, 1936. A. J. LIBERT 2,059,644

COMPENSATING LEVER MECHANISM FOR SHEARS Filed Oct. 22, 1930 3 Sheets-Sheet 2 gwuontoz Nov. 3, 1936. A. J. LIBERT COMPENSATING LEVER MECHANISM FOR SHEARS Filed Oct. 22, 1930 5 Sheets-Sheet 5 Patented Nov. 3, 1936 UNITED STATES PATENT OFFICE GOMPENSATING LEVER MECHANISM FOR SHE ARS

1 Claim.

The invention relates to compensating lever mechanism for automatic sheet metal shears, and more particularly to treadle control for the movable cutter of the shears to regulate the throw and depth of penetration of said cutter and constitutes improvements over the subject-matter of an application for United States Letters Patent filed on or about December 26, 1928 and serially numbered 328,594.

The primary aim of the present invention is the provision of mechanism of this character, wherein the movable cutter of the shears can be shifted by a foot treadle to regulate the length of the stroke or vertical travel of the said outter and the depth of penetration of the latter in the work in the operation of the shears.

Another aim of the invention is the provision of mechanism of this character, wherein there are involved novel connections between a foot treadle and an adjusting element for a movable cutter of the shears to regulate the throw or stroke of the blade for compensation of the adjustment of the setting means for depth of penetration of the movable cutter and also stop penetration at the proper shearing point during the operation of the machine.

A further object of the invention is the provision of mechanism of this character, wherein the cutting blades of the shears can be maintained open and the weight of the foot treadle counterweighted, while the movable cutter of the shears can be regulated for its throw and accurate adjustment had for depth of penetration in the work, as well as to stop penetration at proper shearing point.

Other objects will be in part obvious and in part hereinafter pointed out.

With the above and other objects in view the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings, which show the preferred embodiment of the invention, and pointed out in the claim hereunto appended.

In the accompanying drawings:-

Figure 1 is an elevation of the compensating lever mechanism constructed in accordance with the invention with adjunct parts of the sheet metal shears associated therewith, these being partly in full lines and partly in dotted lines and said mechanism being viewed on line |-l of Figure 2, looking in the direction of the arrows.

Figure 2 is a side elevation of the mechanism, only a portion of the base of the shears being shown therewith.

Figure 3 is an elevation viewed on the line 3-3 of Figure 2, looking in the direction of the arrows.

Figure 4 is a top plan view of Figure 3, viewed on the line 4-4 of Figure 2, looking in the direction of the arrows.

Figure 5 is a sectional view taken on the line 55 of Figure 1 looking in the direction of the arrows.

Figure 6 is a perspective view of the automatic shears with the compensating lever mechanism associated therewith.

Figure '7 is a fragmentary sectional view through the head of the shears.

Figure 8 is a fragmentary end elevation thereof.

Similar reference characters indicate corresponding parts throughout the several views in the drawings.

Referring to the drawings in detail, A designates a portion of the upper stretch of the frame head of the shears and B a portion of the stand or base thereof, the shears constituting the subject matter of an application for U. S. patent, filed December 26, 1928 and serially numbered 328,594. This head A has mounted therein for free rotation an eccentric sleeve C fitted with bearings D for the journal E of a crank F, the latter being projected beyond the free end of the head A as shown in Figure 7 of the drawings. The inner end of the journal E is joined through the medium of a flexible coupling G with a driven shaft H operated by a power unit. The eccentric sleeve C has a lever or handle ID for turning it to regulate the displacement of the upper cutter 39 of the shears. This lever or handle l carries a spring pressed friction ball J located in the overhang K of the said lever or handle and this ball frictionally rides upon the head A.

In the stand or base B of the shears is journaled a horizontal rocker shaft H having its bearing therein and extends from front to rear of the stand or base. On the front end of the shaft ll is fixed a treadle coupling 12, in which is rotatably mounted the shank or stem l3 of a treadle or pedal M. This shank or stem I3 is fitted with an adjustable latching device l which can be adjusted thereon to engage with a keeper l6 integral with the coupling l2 to prevent rotation of the shank or stem therein and corresponding tilting of the treadle" or pedal M or to engage a keeper I! on the stand or base B when the shank or stem is turned in the coupling l2 after depressing the same and tilting the treadle or pedal 14 for locking the rocking shaft II and said treadle or pedal in this position for a purpose presently described.

In some cases the operator does not wish to keep the cutter in set position, but to change it during the operation. For this reason the operator does not wish to latch the treadle, so before starting the operation he sets the latching device l5 that it will engage the keeper l6 and not the keeper On the other hand, if the operator wishes to hold the cutter in adjusted position, he first sets the latching device l5 so that it will not engage the keeper IE but the keeper I! when the treadle I4 is tilted.

On the rear end of the shaft H is loosely journaled a cradle lever I8 having its short arm l9 connected with the lower end of a coiled retractile spring forming a counterweight spring, the upper end of which being fixed or connected to the stand or base B at the proper elevation thereon.

In the cradle 2| of this lever I8 is a compensation spring 22 of the compressible type which ooacts with an abutment 23 formed on and rising from a hub 24 adjustably fixed to the shaft II, which latter is rocked by the treadle or pedal l4.

Connected with the long arm 25 of the lever I8 is a rod 26 which extends upwardly at the rear of the shears and connects with an arm 21 of a bell-crank lever 23, the other arm 29 of the same being linked at 3|] with the throw handle I0 of the shears for regulating the upper movable cutter thereof.

On the frame A of the shears in the path of movement of the throw handle H1 is an adjustable setting device including a set screw 3| supported in a stationary bearing 32 formed on the frame and this screw 3| is provided with a hand hold 33, the said screw serving as a stop for the handle it when actuated to limit the throw of the handle when depressing pedal M to allow the correct penetration of the cutter 39 for cutting the different gauge metals.

It is to be understood that the shaft H is limited in its rocking movement and likewise the shank or stem l3 carrying the treadle or pedal I4 has a corresponding determined movement, so the compressible spring 22 which is of such stiffness that it will not compress until the lever or handle I0 engages set screw 3|, compensates for the setting of the throw handle and adjustment of the screw 3| without disturbance of or interference by the rocker shaft While the spring 20 acts to maintain the upper and lower cutters of the shears open and counterweights the treadle or pedal M.

In the operation of the mechanism hereinbefore described when it is desired to regulate the throw of the upper movable cutter of the shears an operator depresses the treadle or pedal |4 causing the shifting of the throw handle Hi to the determined degree whereupon the said treadle or pedal 4 is tilted to bring the keeper latch l5 into engagement with the keeper I! on the stand or base B, so that the said throw handle will now be maintained in its set position, to regulate the throw of the cutter which is automatically operated.

The screw 3| can be set in its bearing 32 to coact with the throw handle l0 to determine the depth of cutting action or penetration of the cutter and also to stop the penetration at the proper shearing point during the working of the shears.

The treadle or pedal I4 is released by reversely tilting the same or turning it forwardly of the shears by the foot of the operator as will be clearly apparent.

What is claimed is:

The combination of a control device for a movable element, adjustable means for regulating the throw of the control device, a horizontal rocker shaft, a treadle coupling on the shaft, a treadle stern rotatably fitted in the coupling, a treadle carried by the stem, a latching device on the stem, means including a keeper on the coupling and eng'ageable by the latching device for releasably holding the stern against rotation, a locking member on a stand of the control device for engagement by the latching device for maintaining the shaft locked after depression and subsequent rotation of the treadle, said treadle having a movement greater than the control device, and means for compensating the difference in movements of the control device and treadle.

ARTHUR J. LIBERT. 

